There’s a wide range of opinions here. I am of the mind that you can still use it as part of a multisig quorum. I’d personally be a little hesitant to use as a single sig. However if you never updated the firmware after their Recover service was announced you are probably fine even in single sig. 
overall, if I had a single sig and a decent sized stack, personally I’d rather spend the money to switch hardware wallets. For a small stack I personally wouldn’t sweat it. 
Each person has to decide based on their situation.